A sea of troubles.
There are so many problems with the Internet of Things. And what's so funny is that for all the industry is shouting about it (and licking its lips about the coming cash bonanza), almost all of those problems are created by the IT industry itself.
Security in embedded systems is currently laughable. And doesn't seem to be improving, despite the last 20 years of computer history. That's pathetic and inexcusable. Almost no-one who's used a computer in that time hasn't had to deal with spam, incoming viruses and phishing. And coders and engineers use computers more than most.
Everyone is so greedy that there are seemingly as many compteting standards as there are industry players. It's going to be impossible to dominate IoT in the way you could conceivably dominate the operating system market, because you're talking about so many different players. Especially if you're talking about commercial as well as domsetic systems. There are now some alliances, but there seem to be hundreds of them too.
Then we come to data privacy. People are starting to notice Facebook and Google. They may continue to ignore the problem, but society can change very quickly. Politicians can suddenly take notice of a problem, if the electorate shout loudly enough, and suddenly tell all those corporate lobbyists to bugger off. Remember that Germany are increasinly influential in the EU, and their electoare are already deeply concenrned about privacy. They've just got their commissioner put in place to look at it, and there's reasonable evidence to suggest that it was anti-Google elements in the German press (Axel Springer) that helped get the current Commission President his job. The EU may suddenly start pushing for better privacy, so might the electorate. A lot of the IoT and internet companies seem to be blissfully unaware of this risk.
This wouldn't be so much of a problem, except the easiest and cheapest way to run these things is going to be via websites. Otherwise you have to have appliances designed for the control job, which then have to be flexible enough to do all sorts of things. i.e. mini PCs.
The next problem that I think is huge is one that is dear to my heart. Or pisses me off every day in my work (depending on your point of view). The hideous and stupid cheapskatery of the building industry. This is true of both the commercial and domestic lot. The industry is set up to fail, because clients never get involved enough or have their interests properly represented. The only time they do interfere, is to screw everyone over on money. So costs get cut in totally inappropriate ways. This means that there's never going to be wiring for IoT, or places to fit the sensors.
Take an example of something I saw over ten years ago. Central Locking for houses. The idea being that just like a car, you leave, press the button on your keyfob, and everything gets locked, and alarm is set. Or you get a warning if you've left a window open. This would cost almost nothing to do when building a house, but to retrofit it (and not have it look a mess) would cost thousands. The same is true of solar panels (PV or thermal). Installation usually costs more than the equipment, but when you're already building the roof, that installation cost drops to a couple of extra hours work from the guys already onsite.
That throws everything back on wireless. Can anyone think of a wireless installation they've used that's worked flawlessly? And hasn't crapped out at some vital moment? And how many times do you have to explain to people that it might be a good idea to reboot their wireless router before claiming their broadband or computer isn't working? That's one major disadvantage of wireless. As well as interference, buildings with thick internal walls that block signals. Before I've even mentioned hospitals, who're paranoid about wireless signals (although less so than they used to be). Certainly last time we looked at a wireless sensor for work, one of the main target markets was hospitals and so the idea was nixed. Just as well, as I was working up my arguments as to why it wouldn't work in this application anyway - and rather concerned about how enthusiastic people were getting about it.
The place the internet of things should take off is commercial buildings. Many of them have already got BMS systems. Which will take a variety of inputs and can be easily programmed. Many of them have also massively cut back on maintenance, and often no longer have caretakers onsite. So remote reporting is an obvious solution. And many of them suffer from the problem that vital kit is in locked rooms, that it's not always easy to find the keyholder for. Plus there's easy access to wiring ducts, and non-public facing areas to put everything. But I guess that's not cool enough for the Silicon Valley types - and there's no enticing gobs of data to attract anyone either. Also you're dealing with engineers, who're less likely to accept products that are still in beta. Wheras it would actually be a good place to build the industry, due to the ease of retro-fitting stuff.
I'd say it's hard to predict. There are many reasons for the industry to fail to take off. But the fact that so many people have smartphones and tablets means that the control issue is a lot easier. So my feeling is that it's ten years away, as it has been for the last twenty or thirty years. But it only takes a few surprising products to go mainstream, to suddenly kickstart a whole industry - where the technology has been available for a while, but not been properly made to work. Sorry, that's a lot of text to eventually say "I don't know"?